My parents once gave me a blanket for my birthday. It is already shabby, but still I always take it with me to a new place of residence. Always reminds me of home
That's easy: all the Lego sets I racked up over each and every Christmas. Even after taking them apart, I would freehand build stuff that looked like something Victor Frankenstein would be proud of.
My favourite (and regular) provider at the time gave me a 50% discount for my birthday. Many gifts I've received over the years I have no longer, but those memories will always be there. Unless my minds starts to go...